Malaria in children of Tshimbulu (Western Kasai, Democratic Republic of the Congo): epidemiological data and accuracy of diagnostic assays applied in a limited resource setting

BACKGROUND: The literature data on malaria in Western Kasai, DRC, are limited and inadequate. A recent molecular survey there has detected Plasmodium ovale and Plasmodium malariae as mixed infections with Plasmodium falciparum. In Tshimbulu, Western Kasai, during a humanitarian initiative designed to provide children with free preventive screening and to reduce the local high malaria death rate, accurate species identification was performed, in order to collect unambiguous epidemiological data and to evaluate the reliability of locally applied diagnostics. METHODS: Finger pricks provided fresh blood for microscopic analysis (MA), for rapid diagnostic test (RDT) and for molecular diagnostics (MD). MA and RDT were first performed by the local team and then a re-interpretation of the results (on the same slides and on RDT's taken pictures) was conducted in Italy, where MD were performed. RESULTS: The analysis was conducted on 306 children; RDT found 80.9 % as P. falciparum-positive (37.4 % as two-band positive, P. falciparum single infection). MA identified a further four children as positive to P. falciparum and six co-infections with P. ovale. The second RDT evaluation confirmed a similar infection rate (78.2 %) but interpreted as two-band positive a significantly higher share of tests (56.8 %). MA confirmed 80.0 % of the children as malaria positive and, in addition to P. falciparum, identified P. malariae (13.8 %), P. vivax (3.4 %) and P. ovale (2.4 %), and detected Babesia microti in 19 smears. MD confirmed all of the species found (Babesia microti included), classified as mono-infection with P. falciparum a rate of spots comparable to MA revision, and identified all P. ovale as Plasmodium ovale wallikeri. The RDT used locally proved 93.1 % sensitive and 92.1 % specific for P. falciparum. CONCLUSIONS: The malaria prevalence among the children and the presence of four Plasmodium species, highlighted in this study, identified a sanitary issue which proved to be more alarming than expected, as it was worsened by the unpredictable presence of P. vivax and Babesia microti (never before reported in DRC). Each diagnostic tool showed its point of weakness. Therefore, the most correct approach is by the combined use of different, locally available, diagnostic tools

EEG Responses to TMS Are Sensitive to Changes in the Perturbation Parameters and Repeatable over Time

BACKGROUND: High-density electroencephalography (hd-EEG) combined with transcranial magnetic stimulation (TMS) provides a direct and non-invasive measure of cortical excitability and connectivity in humans and may be employed to track over time pathological alterations, plastic changes and therapy-induced modifications in cortical circuits. However, the diagnostic/monitoring applications of this technique would be limited to the extent that TMS-evoked potentials are either stereotypical (non-sensitive) or random (non-repeatable) responses. Here, we used controlled changes in the stimulation parameters (site, intensity, and angle of stimulation) and repeated longitudinal measurements (same day and one week apart) to evaluate the sensitivity and repeatability of TMS/hd-EEG potentials. METHODOLOGY/PRINCIPAL FINDINGS: In 10 volunteers, we performed 92 single-subject comparisons to evaluate the similarities/differences between pairs of TMS-evoked potentials recorded in the same/different stimulation conditions. For each pairwise comparison, we used non-parametric statistics to calculate a Divergence Index (DI), i.e., the percentage of samples that differed significantly, considering all scalp locations and the entire post-stimulus period. A receiver operating characteristic analysis showed that it was possible to find an optimal DI threshold of 1.67%, yielding 96.7% overall accuracy of TMS/hd-EEG in detecting whether a change in the perturbation parameters occurred or not. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that the EEG responses to TMS essentially reflect deterministic properties of the stimulated neuronal circuits as opposed to stereotypical responses or uncontrolled variability. To the extent that TMS-evoked potentials are sensitive to changes and repeatable over time, they may be employed to detect longitudinal changes in the state of cortical circuits

Latent classes of emotional and behavioural problems in epidemiological and referred samples and their relations to DSM-IV diagnoses

Researchers\u2019 interest have recently moved toward the identification of recurrent psychopathological profiles characterized by concurrent elevations on different behavioural and emotional traits. This new strategy turned to be useful in terms of diagnosis and outcome prediction. We used a person-centred statistical approach to examine whether different groups could be identified in a referred sample and in a general-population sample of children and adolescents, and we investigated their relation to DSM-IV diagnoses. A latent class analysis (LCA) was performed on the Child Behaviour Checklist (CBCL) syndrome scales of the referred sample (N = 1225), of the general-population sample (N = 3418), and of the total sample. Models estimating 1-class through 5-class solutions were compared and agreement in the classification of subjects was evaluated. Chi square analyses, a logistic regression, and a multinomial logistic regression analysis were used to investigate the relations between classes and diagnoses. In the two samples and in the total sample, the best-fitting models were 4-class solutions. The identified classes were Internalizing Problems (15.68%), Severe Dysregulated (7.82%), Attention/Hyperactivity (10.19%), and Low Problems (66.32%). Subsequent analyses indicated a significant relationship between diagnoses and classes as well as a main association between the severe dysregulated class and comorbidity. Our data suggested the presence of four different psychopathological profiles related to different outcomes in terms of psychopathological diagnoses. In particular, our results underline the presence of a profile characterized by severe emotional and behavioural dysregulation that is mostly associated with the presence of multiple diagnosis

Coupled thermal and electromagnetic analysis of the NAFASSY magnet

The paper presents an analysis of the current distribution and electromagnetic losses in the NAFASSY magnet carried out with the THELMA code, thanks to a brand-new thermal module coupled with the pre-existing electromagnetic module. The non-linear thermal and electrical properties of both superconducting and copper strands, depending on the local temperature, current density and magnetic field, are taken into account. The model analyses a single turn of the magnet, located in the highest field zone, focusing on the current distribution in the cable, the coupling AC and DC losses during ramped waveforms. The results are then extrapolated to estimate the behaviour of the overall magnet. A description of the models is given, together with a parametric analysis of different boundary conditions and cable discretizations. The analysis shows that, in nominal working conditions, no thermal instability should take place. However, local current redistribution among the strands may occur, mainly driven by the interstrand contact pattern, the local magnetic field and the strand current density

The 2019 Eruptive Activity at Stromboli Volcano: A Multidisciplinary Approach to Reveal Hidden Features of the “Unexpected” 3 July Paroxysm

In July and August 2019, Stromboli volcano underwent two dangerous paroxysms previously considered “unexpected” because of the absence of significant changes in usually monitored parameters. We applied a multidisciplinary approach to search for signals able to indicate the possibility of larger explosive activity and to devise a model to explain the observed variations. We analysed geodetic data, satellite thermal data, images from remote cameras and seismic data in a timespan crossing the eruptive period of 2019 to identify precursors of the two paroxysms on a medium-term time span (months) and to perform an in-depth analysis of the signals recorded on a short time scale (hours, minutes) before the paroxysm. We developed a model that explains the observations. We call the model “push and go” where the uppermost feeding system of Stromboli is made up of a lower section occupied by a low viscosity, low density magma that is largely composed of gases and a shallower section occupied by the accumulated melt. We hypothesize that the paroxysms are triggered when an overpressure in the lower section is built up; the explosion will occur at the very moment such overpressure overcomes the confining pressure of the highly viscous magma above it

Acute adenosine increases cardiac vagal and reduces sympathetic efferent nerve activities in rats

Adenosine is the first drug of choice in the treatment of supraventricular arrhythmias. While the effects of adenosine on sympathetic nerve activity (SNA) have been investigated, no information is available on the effects on cardiac vagal nerve activity (VNA). We assessed in rats the responses of cardiac VNA, SNA and cardiovascular variables to intravenous bolus administration of adenosine. In 34 urethane-anaesthetized rats, cardiac VNA or cervical preganglionic sympathetic fibres were recorded together with ECG, arterial pressure and ventilation, before and after administration of three doses of adenosine (100, 500 and 1000 mu g kg-1). The effects of adenosine were also assessed in isolated perfused hearts (n= 5). Adenosine induced marked bradycardia and hypotension, associated with a significant dose-dependent increase in VNA (+204 +/- 56%, P < 0.01; +275 +/- 120%, P < 0.01; and +372 +/- 78%, P < 0.01, for the three doses, respectively; n= 7). Muscarinic blockade by atropine (5 mg kg-1, i.v.) significantly blunted the adenosine-induced bradycardia (-56.0 +/- 4.5%, P < 0.05; -86.2 +/- 10.5%, P < 0.01; and -34.3 +/- 9.7%, P < 0.01, respectively). Likewise, adenosine-induced bradycardia was markedly less in isolated heart preparations. Previous barodenervation did not modify the effects of adenosine on VNA. On the SNA side, adenosine administration was associated with a dose-dependent biphasic response, including overactivation in the first few seconds followed by a later profound SNA reduction. Earliest sympathetic activation was abolished by barodenervation, while subsequent sympathetic withdrawal was affected neither by baro- nor by chemodenervation. This is the first demonstration that acute adenosine is able to activate cardiac VNA, possibly through a central action. This increase in vagal outflow could make an important contribution to the antiarrhythmic action of this substance.Ministero dell' Istruzione, Universita' e della Ricerca ScientificaConselho Nacional de Desenvolvimento Cientifico e Technologico (CNPq) - Brazil [308016/20092

ROC analysis applied to the DI. ROC curve is depicted as a solid black line, interspersed by blank dots representing the values of sensitivity and specificity (repeatability) associated to single DI values.

<p>The optimal DI value of 1.67% computed according to the Younden index <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010281#pone.0010281-Younden1" target="_blank">[34]</a> is shown as a black dot. Dashed line represents the ROC curve of a random classifier. Gray-shaded region indicates the area under the curve.</p

Divergence Index of all pairwise comparisons between TMS-evoked potentials.

<p>Single DI values computed over the entire post-stimulus period (250 ms) are shown in (A) with the following color-coding: DIs of the C comparisons for changes in the stimulation site, intensity and angle are represented by cyan, black and green dots, respectively, while DIs of NC comparisons are depicted in yellow for same-day sessions and in red for one-week-apart sessions. DI values computed over different temporal windows of interest (0–60 ms, 60–120 ms, 120–250 ms) are reported in (B) with the same color-coding, except for NC comparisons that are summed together and plotted in orange.</p